Venezuelan government demands for more money are jeopardizing the country's biggest company and billions of dollars of foreign investments in oil projects.

Already rattled by low oil prices, an economic crisis, and an international credit crunch, Petroleos de Venezuela SA, or PDVSA, is paying nearly $1.4 billion more in dividends to the government this year than it had planned. Analysts have estimated that Venezuela's currency is overvalued by 30% or more. Instead of further slashing spending and risking social unrest, President...